EIDB switch positions

[2thdoc01]

I got my boat back from storage...2012 RZ2 w EIDB...and the house battery is dead. Obviously dealer didnt charge them. I charged it full, and in a day it went dead.

So i have to put in a new one.

I asked about the switch position, and there is on/off/combined?

What setting would it be normal to run off of, where you can anchor and jam, but still have juice to start? Dealer says on position....

In my old boat it was 1, 2 combined....im confused.

[chpthril]

Your boat has the Blue Sea Dual-Circuit Plus dual battery switch and a diode Isolator.

Launch boat = run switch in the "ON" position.

Park boat at end of day = "OFF"

House loads wired to the house battery will only draw from that battery. When engine is running, both banks receive a charge from the alternator through the ISO.

[2thdoc01]

What is the combined option for?

[chpthril]

Emergency start if the main cranking gets low. It combines both banks in parallel.

[JohnnieMo]

I'm going to pirate this thread as it came up in my google search for what the hell EIDB stands for....

But regardless, I'm trying to help my dad fix is 2006 2500HD Silverado. It has dual batteries and they drain over night. It happens after putting in new batteries. He's been to dealerships, shops etc with no solution. It seems to be worse in the cold.

Either way, rather than fixing this, is it possible to add an isolator such that only one battery gets killed? Is something like this available for trucks?

[chpthril]

Truck batteries are typically just wired in parallel. It would be simple to just add a basic on/off battery switch. Or a heavy duty solenoid with the control switch in the cab.

[JohnnieMo]

Would that not screw up your radio etc. each and every day? Not to mention your power door locks?

[IDBoating]

It has dual batteries and they drain over night.

Suggestions:

Make certain the battery tops are terminals are clean. Gunk that builds up there can provide a current path between the terminals that can drain a battery. If the batteries are wired in parallel, one dirty battery can drain both.

If that doesn't fix it, get a multimeter with a reasonably high DC current feature (Harbor Freight has them for around $5 that will handle 10 amps). Disconnect the negative terminals on both batteries, then put the meter in series between one battery's negative terminal and its negative cable. You should now see how much current is flowing. This is the current that is draining your batteries. DO NOT ATTEMPT TO START THE ENGINE WHILE THE METER IS IN THE CIRCUIT. In fact, leave the key out... you don't need the key for anything you're testing here.

Next, watch the meter and remove the power fuses one by one. Eventually you should find the current drops a bunch when a certain fuse is removed. This will tell you which circuit has the unusually high current draw. Once you know that, use standard troubleshooting techniques to isolate and repair the problem. Remember that there can be fuses EVERYWHERE, including inline fuse holders for things like aftermarket radios and amplifiers, in addition to those in the fuse block. Check them all until you find one that makes the current drop a bunch.

If none of the fuses make any difference, you may have worn insulation on a cable somewhere that is shorting to something. That will be a major PITA to find without a milliohmmeter, which is also a major PITA to find. Here's hoping that the fuse approach reveals the culprit.

Report back!